Conventionally, a solar cell panel is inserted into a metallic outer frame with hot melt interposed as an adhesive or seal material. A solar cell panel has, for example, transparent electrodes provided at the rear side of a glass sheet of a light-receiving face side. Amorphous silicon and thin-film polycrystalline silicon are disposed between the transparent electrodes and the rear-face electrodes. A groove-shaped engagement portion for insertion of the solar cell panel is provided in the metallic outer frame. According to the conventional method, hot melt is coated at the engagement portion of the outer frame, and subsequently the solar cell panel is inserted in the engagement portion, thereby engaging the solar cell panel into the outer frame.
However, holes and the like for installation are provided at the engagement portion of the outer frame. In these circumstances, applying hot melt, which is fluid, at the engagement portion of the outer frame may not be desirable. Also, a large amount of hot melt may be applied at the engagement portion in order to reliably prevent water from entering between the solar cell panel and the outer frame. In this case, excess hot melt overflows from the engagement portion, and a step for removing the excess hot melt is required.
In order to solve these problems related to application of hot melt at the outer frame, a method has been proposed wherein hot melt is applied to the solar cell panel. By applying hot melt on the solar cell panel, it is possible to use fluid hot melt even when assembling the solar cell panel and an outer frame that includes holes for installation. Also, hot melt is applied directly on the solar cell panel, so it is possible to more reliably prevent water from entering the solar cell panel. Additionally a less expensive outer frame may be used with the solar cell panel.
One example of a conventional apparatus and method is provided at Japanese Patent Application No. 2000-243998.
In order to apply a liquid such as hot melt onto the outer peripheral part of a substrate such as a solar cell panel using a conventional coating device, three coating devices are typically necessary to apply respective liquids onto the end face of the substrate, the upper face of the substrate adjacent to the end face, and the lower face of the substrate adjacent to the end face. The three coating devices are respectively provided with a nozzle, a liquid supply valve for supplying liquid to the nozzle, and a liquid passage for supplying liquid to the liquid supply valve from a liquid supply source. Thus, one problem is additional expense incurred in providing a plurality of nozzles, a plurality of liquid supply valves, and a plurality of liquid supply passages. Also, the number of structural components increases, so a large space is required for installing the plurality of coating nozzles.
In addition, a plurality of liquid supply passages is necessarily provided from the liquid supply source to the plurality of coating nozzles, which causes the piping for the plurality of liquid supply passages to become complicated. Furthermore, the operation of positioning the respective plurality of coating nozzles with respect to the substrate takes time, and the operation of adjusting the timing of starting and stopping dispensing by the respective coating nozzles also takes time. In addition, the finish of the seam between respective films formed by the plurality of coating nozzles is not good. More specifically, the seam sticks upward, or bulges out.
Therefore, the object of the present invention is to provide a coating nozzle and coating method that can dispense liquid at the end face of a substrate and at the faces of the substrate adjacent to the end face. Also, the object of the present invention is to provide an inner volume control valve used with the coating nozzle.